聚苯胺衍生物电致变色薄膜的制备与物性研究

采用循环伏安电化学沉积方式分别制备了聚邻甲氧基苯胺(1)和聚邻甲氧基苯胺/邻硝基苯胺(2)电致变色薄膜, 并通过UV-Vis、分光光度仪、场发射扫描电子显微镜(SEM)对其进行性能表征. 结果显示: 变色膜1在不同电压下能实现湖绿色(U＝－0.5 V)和淡紫色(U＝0.9 V)变化, 响应时间约15 s, 最大透光率变化(DT_max)约10% (500 nm)|变色膜2在不同电压下能实现橄榄绿色(U＝－0.9 V)和深酞蓝色(U＝1.4 V)变化, 响应时间约2 s, 最大透光率变化(DT_max)约为20% (497 nm)|SEM测试得到薄膜2的厚度约550 nm, 且不同颜色状态下其表面形貌及导电性能有较大的差别. 由以上结果可以看出: 电致变色薄膜2比1具有更快的响应速度和较好的颜色对比度, 因此薄膜2是更好的电致变色材料.     

PEDOT基光子晶体的制备及其电致变色性能研究

采用改进的Stöber法合成了单分散SiO₂微球, 通过垂直沉积组装成蛋白石结构光子晶体. 再使用电化学法在组装的SiO₂微球表面生成聚(3,4-乙撑二氧噻吩)(PEDOT), 得到核-壳结构的SiO₂@PEDOT光子晶体复合膜. 测试了SiO₂@PEDOT光子晶体薄膜的反射光谱、循环伏安曲线、多电位紫外反射光谱、对比度及响应时间等光学、电化学及电致变色性能. 结果表明, 该光子晶体薄膜在变色时颜色亮丽, 其色差值(26.82)比纯PEDOT薄膜(18.07)提高很多, 并且最大对比度可达39.8%, 高于纯PEDOT薄膜的27.4%, 同时响应时间变快. 此实验结果说明将光子晶体结构引入导电聚合物中, 能够提高其电致变色性能.     

Ag/WO3纳米复合膜的制备及其电致变色性质和器件的研究

通过真空镀膜方法制备的纳米Ag薄膜均匀致密, 表面光滑. 然后通过电化学方法在Ag纳米薄膜上沉积一层三氧化钨(WO3), 制备纳米Ag/WO3复合膜. 并在此基础上构筑五层式玻璃/ITO/纳米Ag-WO3复合膜/固态电解质/聚(3-甲基噻吩)/ITO/玻璃电致变色器件. 实验结果表明, 与传统的WO3膜相比, 纳米Ag/WO3复合膜具有更好的电化学活性、更高的对比度、更短的响应时间, 以及更好的稳定性. 由该复合膜组装的电致变色器件工艺简单, 电致变色性能良好.     

TiO2-PTPAT纳米核/壳结构复合膜的制备及电致变色性能

通过水热法在氟掺杂氧化锡(FTO)导电玻璃基底上制备了垂直生长的二氧化钛(TiO₂)纳米棒阵列, 以TiO₂纳米棒阵列为模板采用电化学聚合法, 原位制备了TiO₂-聚三[2-(4-噻吩)苯]胺(PTPAT)纳米核/壳结构的复合薄膜, 相比于纯PTPAT薄膜, TiO₂-PTPAT复合薄膜显示出更好的电致变色(EC)性能. PTPAT薄膜在600 nm波长下的对比度为28%, 在1100 nm波长下的对比度为60%, 其褪色时间为3.86 s, 着色时间为5.52 s; TiO₂- PTPAT复合薄膜在600 nm波长下的对比度为43%, 在1100 nm波长下的对比度为79%, 其褪色时间为3.35 s, 着色时间为4.43 s, 表明核/壳复合结构薄膜的光学对比度和响应时间性能更加优异. 将PTPAT薄膜和TiO₂-PTPAT复合薄膜作为电致变色层组装成固态EC器件, 基于复合薄膜的器件具有更好的循环稳定性和更高的耐受电压. 复合薄膜在保持PTPAT薄膜原有的EC性能的基础上, 由于有序生长的纳米阵列结构的引入增加了薄膜的比表面积, 为电致变色过程中离子的掺杂和脱掺杂提供了更多有序通道, 从而加快了离子扩散速度. TiO₂阵列的引入也改善了聚合物薄膜与透明导电电极之间的界面结合情况, 从而提升了器件的稳定性.     

D-A型多色电致变色材料的电化学合成与表征

设计合成了两种新型单体, 电化学聚合制得了相应D-A型聚合物: 聚{10,13-二(3,4-乙烯二氧噻吩基)二苯并[a,c]吩嗪}(P1)和聚{10,13-二(4-乙基噻吩-2-基)二苯并[a,c]吩嗪}(P2). 研究发现, 聚合物膜P1在中性态呈现绿色, 且随着电压的增加呈现多种不同的颜色, 其在1600 nm时最大光学对比度达74.8%, 响应时间为0.6 s, 着色效率(CE)为285.8 cm²/C. 聚合物膜P2在氧化态和还原态时分别为灰蓝色和军绿色, 也具有较高的光学对比度, 快速的转换响应以及较高的着色效率. 另外, 这两种导电聚合物都具有较低的光学禁带(E_g)(P1为1.26 eV, P2为1.54 eV). 本研究提供了两种具有优良性能的电致变色材料, 并对其性能参数进行了分析研究.     

离子液体中聚3-己基噻吩的制备及电致变色性质和器件的研究

以室温离子液体1-丁基-3-甲基咪唑六氟磷酸盐[BMIM]PF₆为溶剂及支持电解质,通过电化学方法制备聚(3-己基噻吩)(PHexT)膜。采用循环伏安法和扫描电子显微镜,对膜的电化学性质及形貌结构进行表征。同时通过紫外可见光谱、计时电流、计时库仑以及计时吸收曲线等方法研究聚合物膜的光谱电化学和电致变色特性,并在此基础上制备PHexT膜的电致变色器件。实验结果表明,在离子液体中制备的PHexT膜光滑致密,掺杂态时为蓝色,脱掺杂时为桔红色,并且具有高的颜色对比度 (40%),较短的响应时间 (2.5 s) 和高的电致变色着色效率 (230cm²/C),该膜制成的固态电致变色器件具有很好的电致变色性能和长的循环寿命。     

WO3/PANI核壳结构反蛋白石薄膜的电致变色性能

采用连续离子层吸附法在反蛋白石结构三氧化钨(IO-WO₃)薄膜表面引入导电聚合物聚苯胺(PANI)层, 制备了独特的WO₃/PANI核壳结构反蛋白石薄膜(IO-WO₃/PANI). 探究了IO-WO₃/PANI薄膜的形貌、 组成和电化学行为. 结果表明, 当电位扫描范围为-0.6~1.0 V时, IO-WO₃/PANI复合膜在不同电压状态下会呈现出4种不同的颜色, 分别为蓝色(1.0 V)、 绿色(0.2 V)、 浅绿色(0 V)和蓝紫色(-0.6 V). 与IO-WO₃薄膜相比, IO-WO₃/PANI复合膜的电致变色性能显著提高, 其着色与退色响应时间分别为3.8和6.14 s, 变色效率(CE)值为201.1 cm²/C. 电致变色性能的改善主要归因于WO₃与PANI形成给体-受体体系和核壳反蛋白石等级孔结构, 使得离子快速扩散, 并为电荷转移反应提供更大的表面积. 研究结果表明, IO-WO₃/PANI核壳结构反蛋白石薄膜是一种潜在的多色电致变色材料, 具有广阔的应用前景.     

钒钨酸盐-CdS纳米粒子复合膜的制备与电致变色性能

通过层-层自组装方法制备了由Dawson结构三钒取代型钨酸盐1-K₉P₂W₁₅V₃O₆₂·18H₂O(P₂W₁₅V₃)与CdS纳米粒子构筑的复合膜材料, 研究了CdS纳米粒子添加和复合膜层数对P₂W₁₅V₃多酸复合膜材料电致变色性能的影响. 采用UV, XRD, SEM和循环伏安等测试手段对复合材料的结构和性能进行了表征; 将电化学工作站和紫外-可见吸收光谱联用, 在-1.0~+1.0 V的电压范围内, 对不同层数、 有无CdS纳米粒子复合的的膜材料的电致变色性能进行研究. 研究结果表明, 20层的复合膜材料性能最佳, 光反差为38.05%, 着色时间为3.57 s, 褪色时间为6.94 s, 最大着色效率达到94.04 cm²/C, 实现了从无色、 蓝色到蓝紫色, 再到无色的可逆颜色变化, 相对于单独P₂W₁₅V₃膜, 光反差提高46.07%, 着色效率提高96.53%, 电致变色性能显著提高.     

水溶性共轭聚电解质的制备及在有机电致变色器件中的应用

制备了聚噻吩电解质聚[3-(1'-丙氧基-3'-磺酸)噻吩](PTH-n₃-SO₃H). 以铂线和ITO玻璃作为电极, PTH-n₃-SO₃H的水溶液作为支持电解质, 分别以齐聚噻吩衍生物5,5"'-双醛基-2,2': 5',2": 5",2"'-四噻吩(4T-2CHO)和5,5"'-双氰基-2,2': 5',2": 5",2"'-四噻吩(4T-2CN)薄膜作为电致变色活性层, 组装了有机电致变色器件. 研究了4T-2CHO和4T-2CN的电致变色性能, 同时考察了PTH-n₃-SO₃H水溶液作为支持电解质在有机电致变色器件中的应用. 研究发现, 当进行电化学掺杂和去掺杂时, 4T-2CHO膜发生从黄色到蓝绿色的可逆变化, 4T-2CN膜发生从淡黄色到蓝色的可逆变化. 结果表明, PTH-n₃-SO₃H水溶液可以作为支持电解质用于有机电致变色器件.     

金属-超分子聚合物的合成及其多色电致变色器件

本文合成了一种多齿配体化合物——1,4-双(2,2′:6′,2′′-三联吡啶-4′-基)苯及其Fe/Ru金属-超分子聚合物——Poly Fe和Poly Ru,同时以喷涂在ITO导电玻璃上的Fe/Ru金属-超分子聚合物膜为工作电极、0.1 mol/L Li Cl O4水溶液为电解质,并添加K_3Fe(CN)_6为电化学互补材料,制作了系列电致变色器件.由Poly Fe和Poly Ru的组合,可以得到从Poly Fe的蓝紫色渐变到Poly Ru橙红色的彩色薄膜及其多色电致变色器件,器件响应速度快(2 s),褪色电压0.9~1.2 V,着色电压0 V,最大光学对比度约57%.添加K_3Fe(CN)_6后,器件的寿命得到极大提高.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.